WHATEVER happened to the unwritten rule, which applies to players AND COACHES, about keeping criticism of each other in the locker room? Certainly nobody can accuse Jeff Van Gundy (or Danny Ainge and others) of breaking that principle; Van Gundy has never adhered to it, in the first place.

Dave Checketts ought to hire Danny Whelan to teach the Knicks’ coach how Red Holzman protected his players in front of the media as opposed to fingering them. Or, at the very least, have the common decency to invite the team’s former trainer to participate in the next Garden alumni function.

Be honest with yourselves, though, not even those who were chanting Van Gundy’s name last season should be surprised he branded the Knicks “mentally weak.” You’re supposed to take on the personality of your coach.

Four-year guarantee or not, Van Gundy had best conjure up a new method of motivation; veterans can only be emotionally whipped and publicly admonished so often before they become anesthetized and antagonistic, if they aren’t already. They certainly came ready to roll over against the Jazz and Suns.

IF Rod Strickland and coach Gar Heard are unable to form a productive working relationship, it’s believed the Wizards wouldn’t be against trading their starting point guard; the Knicks, of course, would love to bring him back home.

Naturally, it’s obligatory for woeful Washington to secure a pure playmaker in return. No question, Strickland’s mind is elsewhere (I’m told he’s mired in personal problems). And, yes, his body is weeks behind the opposition (due to a DWI trial, as well as excused and unexcused missed practices). Still, his teammates undoubtedly like and look to him.

Clearly, the Wizards need what Strickland has to offer when he’s not pre-occupied, panting for breath or pounding the ball. Consequently, if the exceedingly overpaid and vastly overestimated (by GM Wes Unseld and owner Abe Pollin, anyway) team hopes to improve later, if not now, Strickland cannot be exchanged for the likes of Chris Childs and/or Charlie Ward. Or Derek Fisher and Robert Horry. Or Lindsey Hunter and Loy Vaught.

If you can’t get equal or near-equal value, why bother? At least the Wizards know what they’re not getting from Strickland. Moreover, backup Chris Whitney, a shooter first and foremost, isn’t prepared to distribute the ball on a full-time basis, either.

In other words, Unseld better think twice before exchanging his expensive ($10 million guarantee this season and next) headache for inferior talent. Not that it has stopped Unseld before; see Chris Webber-Mitch Richmond exchange. As far as I can ascertain, Unseld abruptly stopped contributing to the well-being of the franchise the night he made his last outlet pass.

At the same time, before the Knicks reach out for Rod (one of my favorites), they ought to do their homework into what’s troubling him, or risk being pointed in the wrong direction.

On the subject of Richmond, numerous people throughout the league swear (not that they know for sure) Richmond’s ailing knee isn’t his primary problem. The consensus is, the recently signed free agent stayed put this summer simply to get paid ($10M per for three years) as much as possible, and now he’s trying his hardest to get traded. It’s as if the Wizards paid Richmond to retire.

One way or the other, Richmond is averaging just under 10 points, his worst output (by half) in his 12 pro seasons. He’s deceiving himself if he thinks he’s remotely desirable. Who’d want to take a chance on him at this (st)age?

Furthermore, Richmond’s (base year) contract is virtually untradeable. League cap rules prohibit the Wizards from assuming more than $5M worth of salary in exchange for Mitch, whereas any team interested in taking him must have $10M worth of cap room; only the Clippers and Bulls are under the cap.

This might be the last time this season the Wizards are ever mentioned in this space, so I might as well purge all thoughts on them from my system:

Before Ike Austin went for 20 points and 13 rebounds in Thursday’s win over the Raptors, you couldn’t have swapped him for Brent Barry. Actually, you still can’t.

I defy you to name a player who’s more overpaid than Juwan Howard. I mean, other than Chris Dudley.

IN CASE you missed the suspense of the Bulls sending Shaquille O’Neal (41 points, 17 rebounds and seven blocks) to the welfare line for 31 exhilarating free throws, he downed 19 of ’em. Seven of the 20 teams playing Friday evening didn’t hit that many.

Dog Jerry Krause’s Bulls all you want, but they’ve become the undisputed masters of garbage time. Practice makes perfect.

A few days ago, one of the league’s elite GMs wrote off Brand as the second coming of Armen Gilliam. And to think I almost dubbed him “Generic.”

I’M CONFUSED, does Danny Ferry have two or three more years remaining on his original Clipper contract?

Talk about respect and lack thereof, Karl Malone gets a constant call on a fadeaway jump shot from 18 feet (who’s dumb enough to touch him out there?), whereas Stephon Marbury hears no whistle (despite plenty of contact with Christian Laettner) on a game-tying drive in a final-second loss to the Pistons.

Mike D’Antoni has given Dan Issel a vote of confidence.

Note to all you disgruntled college graduates: Do you really think, had Leon Smith not jumped from high school to the NBA, he’d be sane today? Give me a commercial break. As if the pros and Don Nelson are responsible this kid’s messed-up mind.

According to 76er stat freak Harvey Pollack, Allen Iverson is the smallest player ever to led the league in tattoos.

Latrell Sprewell gave away 200 tickets for last night’s return to Oakland, in return for a promise they didn’t see anything.

Checketts is downplaying reports of the Knicks-stripper escapade in Charleston as just another City Dancer tryout.